Grafts et al. 



234 — 



Water in Plants 



Cells, anatomy of, 59-61 



hardened, 134 



minimum volume of, 98 



osmotic properties and transpiration, 194 



osmotic quantities of, 73-110 



plasmolytic behavior of, 122-126 

 Cell walls, as cellular components, 59-61 



chemical composition of, 62-65 



dehydration of, 193 



elastic nature, 85, 172, 193 



imbibition by, 107, 193 



inelastic stretching, 114 



intercellular substance of, 62 



internal leaf surface and, 195 



permeability of, 81 



plastic behavior, 85, 101, 140 



structure of, 62-65, 192-193 



water in, 62-65, 155 

 Cell water relations {see Water relations) 

 Cellophane, use in stomatal studies, 197 



membrane, permeability of, 81 

 Cellular proteins, dissociation of, 145 

 Cellulose, hydration of, 24, 63-65, 155 

 Centaurea repcns, herbicide movement in, 157 

 Chaetomorpha linutn, water exosmosis from, 80 

 Chamacrops humilis, sap expression from, 120, 



123 

 Chara, solute accumulation in, 38 

 Chelate ring, 22 



Chiasmata, water deficit and, 203 

 Chlorella, water deficit and photosynthesis, 201 

 Chloride ion, membrane permeability to, 144 

 Chloroform, leaf permeability to, 193 

 Chlorosis, injection treatment of, 159 

 Chodat-Hecht filaments, 85 

 Citrus grandis, internal leaf surface of, 195 

 Citrus limonum, freez. pt. of sap, 120 

 Coacervate formation, 69 

 Cobalt chloride paper, transpiration detn. with, 



186, 197 

 Coefficient of diffusion, evaporation and, 181, 



182, 183 

 Coffea, rate of sap flow in, 169 



arabica, dye movement in stem of, 157 

 Cohesion, hydration and, 138 



calculated, for water, 46, 155 



theory of water movement, 154, 204 

 Cohesive force, of plant sap, 155 

 Cold hardiness, 117, 120, 121, 134 

 Coleus, rhythmic fluctuations in transpiration, 



191 

 Colloidally bound water (.see Bound water) 

 Colloid osmotic pressure, 97 

 Colloids, vacuolar, 69, 113 

 Companion cells, OP of, 99, 100 

 Conducting elements, cone, of sap in, 100 

 Conifers, rate of sap flow in, 169, 172 

 Convolvulus arvcnsis, herbicidal translocation 



in, 157 

 Corn, water absorption by, 153 



water content of, 62 



water loss from hybrid, 197 

 Cortex, OP of, 100 

 Cortical rays, OP of, 100 

 Cotton, water uptake by, 24 

 Covalent bonds, 22, 29, 63, 138, 192, 193 

 Crocus, intercellular pressure in, 102 

 Cryoscope, 91-92 



calibration curve for, 94, 95 

 Cryoscopic values of OP, 112, 114, 115, 118, 



127 

 Cryoscopy, 90-95, 126 



expression of sap for, 90-91 



freezing point detn. in, 93-95 



of tissues vs. bathing solns., 126-127 



osmotic pressure detns. by, 90-95, 99 



physical principles, 92-93 

 Cucurbita (see also Squash), translocation in, 

 175 



water continuity in, 161 

 Curly-top virus, translocation of, 176 

 Cuticle, and transpiration, 192 



composition of, 187, 193 



fissures in, 188 



thickness of, 187 



wettability of, 187, 188 

 Cytoplasm (see also Protoplasm), adhesion of, 

 82, 83 



hydration of, 69, 125 

 Cystosira barbata, cryoscopy of sap, 127 



Debye-Huckel theory, 7 

 Dehydration, of ectoplasm, 134 



(see also Water deficit) 

 Dendrograph, 157 

 Deplasmolysis, 83, 84, 89, 114 



injury, 134 



values, 116 

 Dianthus barbatus, wettability of cell walls of, 



193 

 Dichlorophenoxyacetic acid, translocation of, 177 

 Dielectric capacity, 6 

 Dielectric constant, 4, 25, 31 

 Differential ion migration, 142 

 Differentially permeable membrane, 43, 49, 79- 



81 

 Differentiation, water conduction and, 156 

 Diffuse porous trees, rate of sap flow in, 171 

 Diffusion, capacity, 196 



coefficient, 182, 183 



constant, 80 

 Diffusion pressure, defined, 43-44 



effect of cutting xylem on, 157 



energy reduction and, 29 



evaluation of, 55 



evaporation and, 182 



factors affecting, 151 



internal water movement and, 172 



lowering, 48 



of water, 192, 198 



of solvent, 55-57 



water movement and, 154 

 Diffusion pressure deficit, and active water re- 

 lations, 111-113, 131-132 



as an osmotic quantity of plant cells, 71-77 



concept of, in osmotic systems, 50-52 



defined, 44, 71 



electrokinetic component of, 144 



freezing of tissue and, 133 



gradient, 108-109, 164 



growth and, 153 



in root, 164 



in stem, 165 



magnitude and fluctuation of, 105-107, 165 



methods of measuring, 98, 101-105 



of atmosphere, 189, 190, 191 



other terms for, SO 



passive absorption and, 149 



transpiration and, 193, 197 



water absorption and, 153 



wilting and, 163 

 Dihydrol, 5, 13 

 Dihydrone, 5 

 Diraer, 22 

 Dipole, 20, 21 



Disease, effect on transpiration, 198-200 

 Ditylum brightwellii, stimulation plasmolysis in, 



124 

 Diurnal fluctuations, in root pressure, 150 



in transpiration, 189, 190, 191 



in stomatal opening, 192 

 DOg, (OP by deplasmolysis), 115, 116 

 DPD (see Diffusion pressure deficit) 

 DPDu (Diffusion pressure deficit, normal), 131 

 Drosera rotundifolia, OP in tentacles of, 125 

 Drought resistance, evidence for active water 



relations, 132-136 

 Drought resistant plants, 206 



